Improved long-term storage of hybridomas at -80 degrees C using a bovine milk derivative.

A medium comprising 40% bovine milk fraction and 10% DMSO (medium A) was used for the long-term storage of hybridomas at -80 degrees C. The viability of the cells, their growth recovery and ability to secrete antibody were studied and the results were compared to those obtained after storage in a medium containing 40% fetal calf serum and 10% of DMSO (medium B). Hybridomas have been kept for 2 years in medium A; the viability of such cells was 75%, the cells were healthy (electron microscopy), they rapidly proliferated when they were cultured in RPMI supplemented with 10% FCS or with 9% milk fraction + 1% FCS and they released measurable levels of antibody. In contrast, hybridomas stored under the same conditions but in medium B died after 6 months.